Propulsion from combustion of solid propellant pellet-projectiles

ABSTRACT

Propulsion from combustion of solid propellant pellet-projectiles for providing a useful propulsion that has the advantages of both solid and liquid propulsion engines, and also can make use of either solid chemical propellants or fissionable nuclear material as the fuel. Preferred methods and systems can include a storage chamber for storing solid propellant pellets, a feeding system having a pellet feeding channel and a pellet feeding mechanism connected to the storage chamber and to a gun assembly, which is positioned along a longitudinal axis to eject the pellets at a certain velocity. A triggering system positioned between gun assembly and thrust chamber can initiate the propellant pellet-projectile, and a thrust chamber having a combustion chamber for combustion of propellant pellet-projectile with an exhaust nozzle. Additionally, an auxiliary power system can be used to power the components and various electrical and electronic systems that may be present in the invention for controlling the engine components. The gun assembly may include an ejector mechanism for ejecting the propellant pellets through at least one barrel. The triggering system can produce a medium creating an ambience for the initiation of propellant pellet-projectiles. Methods and systems can be used for space and rocket crafts, turbojets and ramjets.

This invention claims the benefit of priority of U.S. Provisional PatentApplication 60/347,451 filed Nov. 1, 2001, and U.S. Provisional PatentApplication 60/333,300 filed Nov. 14, 2001, and this invention relatesgenerally to propulsion systems and more specifically it relates tomethods and systems for the propulsion from combustion of solidpropellant pellet-projectiles for providing a useful propulsion methodthat would have the advantages of both solid and liquid propulsionengines, and also can make use of either solid chemical propellants orfissionable nuclear material as the fuel.

BACKGROUND AND PRIOR ART

Propulsion systems have been in use for years. See U.S. Pat. No.5,063,735 to Colgren. The typical propulsion system can include solidpropellant motors, liquid propulsion engines, jet engines, and acombination of jet engine and solid motor such as solid propellant gasgenerator to start a jet engine and Rocket-powered ducted fan engine.

A main problem with conventional solid propulsion systems are thedifficulties in thrust control. Another problem with conventional solidpropulsion systems are complications involved in the reuse of solidmotor case and other parts. Another problem with conventional solidpropulsion systems is that the chamber enclosing the solid charge mustbe strong enough to withstand the heat and high pressures of combustion.

A problem with liquid propulsion rocket engines is that they containvolatile, toxic, corrosive and/or cryogenic propellants. Hence theengine is usually filled a short time before firing, thus requiringcomplicated and lengthy pre-fitting preparations.

A problem with Rocket-powered ducted fan engine is that it can work onlyas a toy vehicle power plant. Also, only about fifty percent of exhaustgases are available for useful propulsion.

The prior art devices described above would not as suitable forproviding a useful solid propulsion method that would have theadvantages of both solid and liquid propulsion engines. Additionally,these prior art devices cannot make use of either solid chemicalpropellants or fissionable nuclear material as the fuel.

SUMMARY OF THE INVENTION

The first objective of the present invention is to provide a method andsystem for providing propulsion from the combustion of solid propellantpellet-projectiles having the advantages of both solid and liquidpropulsion engines.

The second objective of the present invention is to provide a method andsystem for providing propulsion from combustion of solid propellantpellet-projectiles that can make use of either solid chemicalpropellants or fissionable nuclear material as the fuel.

The third objective of the present invention is to provide a method andsystem for providing propulsion from combustion of solid propellantpellet-projectiles that can be incorporated into jet engines and be usedfor jet aircraft.

The fourth objective of this invention is to provides a method andsystem for providing propulsion from combustion of solid propellantpellet-projectiles that can be used as propulsion for rockets and spaceflights.

The fifth objective of the present invention is to provide a method andsystem for providing propulsion from combustion of solid propellantpellet-projectiles that can be used for thrust control and reusabilityof the engine.

The sixth objective of the present invention is to provide a method andsystem for providing propulsion from combustion of solid propellantpellet-projectiles having advantages over liquid propellant engines suchas but not limited to higher volumetric loading of propellants andability to throttle.

The seventh objective of the present invention is to provide a methodand system for providing propulsion from combustion of solid propellantpellet-projectiles that can have the advantages of using solidpropellants such as but not limited to storability and low cost ofmaintenance.

The eight objective of the present invention is to provides a method andsystem for providing propulsion from combustion of solid propellantpellet-projectiles that can make use of the reliability of solidpropellants.

A preferred embodiment of the invention includes a storage chamber wheresolid propellant pellets are stored, a feeding system having a pelletfeeding channel and a pellet feeding mechanism with one end of the saidchannel connected to the storage chamber and other end to a gunassembly. The gun assembly can be positioned along a longitudinal axisto eject the pellets in the direction of said longitudinal axis at acertain velocity, a triggering system positioned between gun assemblyand thrust chamber along said longitudinal axis for initiating thepropellant pellet-projectile, and a thrust chamber having a combustionchamber where combustion of propellant pellet-projectile takes place andan exhaust nozzle with said combustion chamber positioned between thetriggering system and exhaust nozzle along said longitudinal axis.Moreover there is an auxiliary power system that can be used to powerthe pellet feeding mechanism, gun assembly, triggering system andvarious electrical and electronic systems that may be present in theinvention for controlling the engine components.

The invention can additionally include a housing whose axis is the saidlongitudinal axis, covering mainly the gun assembly, triggering system,and thrust chamber. The storage chamber is an enclosed space for storingthe propellant pellets of specific shape profile. The storage chambermay include an outlet and a lid for allowing storage of propellantpellets. The feeding system consists of a feeding channel having aninlet and an outlet, and a feeding mechanism. The feeding mechanismdrives the pellets from the storage chamber through the feeding channelinto the gun assembly. The gun assembly can include an ejector mechanismand barrel. The ejector mechanism ejects the propellant pellets throughthe barrel.

The gun assembly can have more than one barrel for ejecting thepropellant pellets. The barrel gives direction to the propellant pelletsejected. The triggering system can produce a medium that could create anambience for the initiation of propellant pellet-projectiles. The thrustchamber generally consists of a combustion chamber and an exhaustnozzle. The thrust chamber is shielded on the inside with material thatcould withstand the heat and high pressures of combustion of propellantpellets. Also the said shielded chamber would withstand the shocks ofdetonation. Moreover for the turbojet mode of the invention, a turbinemounted on a hollow shaft in between combustion chamber and exhaustnozzle along the said longitudinal axis may be present. The auxiliarypower system can be used for powering various systems within theinvention. These above mentioned systems might include pellet feedingmechanism, gun assembly, triggering system, and the various electricaland electronic systems that may be present in the invention forcontrolling the various engine components. Also, the auxiliary system inthe case of turbojet mode of the invention can be used to power the fanand a compressor.

Further objects and advantages of this invention will be apparent fromthe following detailed description of a presently preferred embodimentwhich is illustrated schematically in the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic sectional elevation view of a preferred embodimentof he present invention in rocket or space mode using only solidpropellants.

FIG. 2 is a schematic sectional elevation view of a preferred embodimentof the present invention in rocket or space mode using both solid andliquid propellants.

FIG. 3 is a schematic sectional elevation view of a preferred embodimentof the present invention in turbojet mode using only solid propellants.

FIG. 4 is a schematic sectional elevation view of a preferred embodimentof the present invention in turbojet mode using both solid and liquidpropellants.

FIG. 5 is a schematic sectional elevation view of a preferred embodimentof the present invention in ramjet mode using only solid propellants.

FIG. 6 is a schematic sectional view of a preferred embodiment of thepresent invention in ramjet mode using both solid and liquidpropellants.

FIG. 7 is a schematic sectional elevation view of a preferred embodimentof the present invention in scramjet mode using both solid and liquidpropellants.

FIG. 8 shows an enlarged sectional view of using two or more barrelswith a single ejector mechanism in the gun assembly of the previousembodiment figures.

FIG. 9A shows an enlarged view primer being used as a triggering systemfor the above embodiments.

FIG. 9B shows an enlarged view of using a liquid propellant to initiatethe solid propellant pellet as a triggering system for the aboveembodiments.

FIG. 10A shows a convergent nozzle for use with the above embodiments.

FIG. 10B shows a divergent nozzle for use with the above embodiments.

FIG. 10C shows a convergent-divergent nozzle for use with the aboveembodiments.

FIG. 10D shows a moveable surfaces nozzle for use with the aboveembodiments.

FIG. 11 shows a schematic view of a rocket/space application for usewith the embodiments of FIGS. 1-2.

FIG. 12 shows a schematic view of a turbojet application for use withthe embodiments of FIGS. 3-4.

FIG. 13 shows a schematic view of a ramjet application for use with theembodiments of FIGS. 1-2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before explaining the disclosed embodiments of the present invention indetail it is to be understood that the invention is not limited in itsapplications to the details of the particular arrangements shown sincethe invention is capable of other embodiments. Also, the terminologyused herein is for the purpose of description and not of limitation.

Turning now descriptively to the drawings, in which similar referencecharacters denote similar elements throughout the several views, theattached figures illustrate a propulsion from combustion of solidpropellant pellet-projectiles, which can include a storage chamber wheresolid propellant pellets are stored, a feeding systems having a pelletfeeding channel and a pellet feeding mechanism with one end of the saidchannel connected to the storage chamber and other end to a gunassembly, a gun assembly positioned along a longitudinal axis to ejectthe pellets in the direction of said longitudinal axis at a certainvelocity, a triggering system positioned between gun assembly and thrustchamber along said longitudinal axis for initiating the propellantpellet-projectile, and a thrust chamber having a combustion chamberwhere combustion of propellant pellet-projectile takes place and anexhaust nozzle with said combustion chamber positioned between thetriggering system and exhaust nozzle along said longitudinal axis.

The invention can use an auxiliary power system that can be used topower the pellet feeding mechanism, gun assembly, triggering system andvarious electrical and electronic systems that can be present in theinvention for controlling the engine components.

Furthermore the invention can include a housing whose axis is the saidlongitudinal axis, covering mainly the gun assembly, triggering system,and thrust chamber. The storage chamber is an enclosed space for storingthe propellant pellets of specific shape profile. The storage chambermay include an outlet and a lid for allowing storage of propellantpellets. The feeding system can consists of a feeding channel having aninlet and an outlet, and a feeding mechanism. The feeding mechanismdrives the pellets from the storage chamber through the feeding channelinto the gun assembly. The gun assembly can also include an ejectormechanism and barrel. The ejector mechanism ejects the propellantpellets through the barrel. The gun assembly can have more than onebarrel for ejecting the propellant pellets. The barrel gives directionto the propellant pellets ejected. The triggering system can beequipment, which produces a medium that would create an ambience for theinitiation of propellant pellet-projectiles. The thrust chambergenerally consists of a combustion chamber and an exhaust nozzle. Thethrust chamber is shielded on the inside with material that couldwithstand the heat and high pressures of combustion of propellantpellets. Also the said shielded chamber would withstand the shocks ofdetonation. Moreover for the turbojet mode of the invention, a turbinemounted on a hollow shaft in between combustion chamber and exhaustnozzle along the said longitudinal axis can be present. The auxiliarypower system can be used for powering various systems within theinvention.

These above mentioned systems can further include pellet feedingmechanism, gun assembly, triggering system, and the various electricaland electronic systems that can be present in the invention. Also, theauxiliary system in the case of turbojet mode of the invention canadditionally power other equipment such as but not limited to the fanand a compressor.

The main components of the preferred embodiments will now be described.

Solid Propellant Pellets

The invention can use solid propellant pellets that are either solidchemical propellants or fissionable nuclear material. However the size,shape, mass or type of the solid propellant pellets would not limit thescope of the invention. The solid chemical propellants can be eitherhomogeneous or heterogeneous.

The dimensions and shape of the pellet depends on how fast the completecombustion or detonation of the pellet takes place in flight, afterpassing through the medium produced by triggering system.

For example a pellet of average outer dimension of 0.25 inch, theinitiation time will range from a few nanoseconds to a few millisecondsand the total combustion time will range from a few microseconds to afew hundredth of a millisecond. For a specific size of a pellet bothinitiation time and total combustion time mainly depend on initiationmedium, material, composition, density and shape of the propellantpellet.

A solid chemical propellant pellet can be either a regular chemicalpropellant or chemical explosive. The solid chemical explosivepropellant can be such as but not limited to TNT, RDX, lead azide, amixture of different explosives and the like. A homogeneous solidchemical propellant can be such as but not limited to nitrocellulose(mono-base propellant) or combination of nitrocellulose andnitroglycerine, to which a plasticizer is added (double-basepropellant). A composite or heterogeneous propellant can be such as butnot limited to a mixture of Aluminum Powder as fuel, AmmoniumPerchlorate as oxidizer, Iron Oxidizer Powder as catalyst, PolybutadieneAcrylic Acid Acrylonitrile as rubber-based binder and Epoxy CuringAgent.

A fissionable nuclear material solid propellant pellet can be such asbut not limited to highly enriched plutonium-239 and uranium-235.

Additionally, the slid chemical propellant pellet used can be a fuelwithout oxidizer, in that case there should be an availability of someform of oxidizer in the combustion chamber 102 which will be describedlater in more detail. The selection of nuclear propellant as a fuel forthe invention is mostly limited to space flights, due to the risk ofradiation and hazardous nuclear residue emission from the engine.

Fuel without oxidizer pellets can be such as but not limited to powderedaluminum, beryllium, lithium, sodium or magnesium along with additivessuch as but not limited to Iron Oxidizer Powder as catalyst,Polybutadiene Acrylic Acid Acrylonitrile as rubber-based binder andEpoxy Curing Agent. Again for combustion there should be an availabilityof some form of oxidizer in the combustion chamber preferably in thegaseous form such as but not limited to Oxygen, Ozone or Nitrous Oxide.

Storage Chamber 20

Referring to FIGS. 1-6, the storage chamber 20 is preferably an enclosedspace for storing the propellant pellets of a selected shape profile tobe described in greater detail later. The storage chamber can include anoutlet and a lid for allowing storage of propellant pellets. As shown inFIGS. 1 through 6, the storage chamber 20 is preferably an enclosedspace having an outlet 24 and can include a lid 22 (FIGS. 3-6). Thestorage chamber 20 can be constructed of various materials such as butnot limited to metal, fiberglass, composites, and the like. Depending onthe solid propellant material stored, the storage chamber 20 can includeadditional protections or equipments for ensuring the safe storage ofpropellant pellets. For example, for nuclear propellants, the storagechamber can be equipped with materials that can shield of radiation. Theshield can be such as but not limited to lead or tungsten shielding.

Feeding System 40

Referring to FIGS. 1-6, the feeding system can include a feeding channelhaving an inlet and an outlet, and a feeding mechanism. The feedingmechanism drives the pellets from the storage chamber through thefeeding channel into the gun assembly. As shown in FIGS. 1 through 6,the feeding system 40 preferably includes a feeding channel 42 and afeeding mechanism 48. The feeding channel 42 is preferably a hollowpassage having an inlet 44 and an outlet 46, however various othermethods of pellet transportation may be utilized as can be appreciated.One skilled in the art of mechanisms can appreciate that the feedingmechanism 48 can be chosen from a variety of mechanisms that assist inthe feeding of propellant pellets.

The feeding mechanism 48 can be such as but not limited to conveyermechanism driven by auxiliary power system or compressed gas (tappedexhaust gases) feeding pellets from the storage chamber 20 to the gunassembly 60. In the case of conveyer mechanism, the conveyer collectsthe pellets from the storage chamber 20 through the feeding channel 42and delivers them to the gun assembly 60. The conveyer can be such asbut not limited to chain or belt with space for holding pellets alongits face. Again the material for conveyer can be such as but not limitedto metal, rubber or polymers.

The feeding channel 42 in the case of multi-barreled gun assembly 60 canbe either a single channel feeding all the barrels 64 or multiplechannels in which each channel feeding each barrel 64 driven by a singleor multiple feeding mechanisms 48.

Gun Assembly 60

Referring to FIGS. 1-6, the gun assembly can include an ejectormechanism and barrel. The injector mechanism ejects the propellantpellets through the barrel. The gun assembly can have more than onebarrel for ejecting the propellant pellets. The barrel gives directionto the propellant pellets ejected. As shown in FIGS. 1 through 6, gunassembly 60 preferably includes an ejector mechanism 62 and barrel 64.Again, one skilled in the art of mechanisms can appreciate that theejector mechanism 62 can be chosen from a wide variety of mechanismsthat assist in the ejection of propellant pellets at a certain velocity.The ejector mechanism 62 can be such as but not limited to the mechanismof propelling the pellets using pressurized or compressed gases (tappedexhaust gases). Barrel 64 can be a tubular component formed from metal,and the like. The Barrel 64 can be single barreled or multi-barreled. Ina multi-barreled gun assembly 60, the propellant pellets can be ejectedfrom all the barrels at one time. Alternatively, the propellant can beejected in a specific sequence such as but not limited to one afteranother.

Triggering System 80

The triggering system 80 can be equipment, which produces a medium thatcreates an ambience for the initiation of propellant pellet-projectiles.As shown in FIGS. 1 through 6, triggering system 80 can produces amedium that creates an ambience for the initiation of propellantpellet-projectile. The said medium can be a generator such as ones thatproduce anyone of a flame, a laser emission, microwave radiation, aneutron emission in the case of nuclear propellant pellet-projectile, orany other medium that initiate the combustion of propellantpellet-projectile.

The flame generator can be such as but not limited to flame and heatgenerated by combustible gases or liquid fuels. Here the flame generatorproduces heat such that the propellant pellet passing through theenvironment produced by the said flame generator gets initiated. Thetemperature developed by the flame generator depends on the type ofpropellant material used. For example depending on the type and speed ofpropellant pellet projectile, the temperature of the flame ranges fromapproximately 400 K to approximately 5000 K.

Laser generator produces CW (continuous wave) or pulsed laser. The laserproduced can be such as but not limited to Diode Laser or YAG laser. Thesolid propellant pellets get heated while passing through the lasermedium, thus causing the initiation. The required type of laser dependson the propellant used in the pellet. This is because differentmaterials absorb energy from different wave lengths. For example a nearinfra-red laser diode (approximately 800 to approximately 2000 nm) thatemits a short duration pulse (approximately 1 to approximately 50 ms)can initiate a propellant pellet of certain material.

Microwave generator produces microwave radiations, such that themicrowave sensitive propellant pellet absorbs microwave energy and getsheated, causing initiation of the propellant pellet. The frequency ofthe microwaves generated is likely to be in the range of approximately0.1 GHz to approximately 100 GHz. The required energy density of themicrowaves depends on the propellant used in the pellet. The triggeringsystem 80 can be any equipment that produces a medium of initiationmentioned above. The triggering system 80 generally surrounds the pathof the propellant pellet-projectiles, such that the medium of initiationinteracts with the said projectiles.

The triggering system 80 can include but not be restricted tocylindrical shape depends on how the generator of the medium producesthe initiation of propellant pellets is arranged.

Additionally, the triggering system 80 can be shielded 88 on the inside,covering the path of the propellant pellet-projectile, that resists andsafeguard the triggering system 80 from the heat and high pressures ofpremature detonation of propellant pellet.

The above mentioned shield can be such as but not limited to ceramics orheat resisting alloys. Moreover, the shield should allow the mediumproduced by the triggering system to pass through.

Alternatively, the initiation of propellant pellet-projectiles can occurwithout the triggering system 80. One can be timed detonation in which aprimer 350 attached to solid propellant pellet 300, such that the primerwould trigger the combustion of solid propellant pellet. The primer 350is an explosive charge that triggers the combustion of solid propellantpellet 300. The ignition of said primer can be done while the propellantpellets leave the gun assembly 60. The timing depends on the delaybetween the combustion of primer 350 and the combustion of solidpropellant 300 present in the pellet.

Still alternatively, the invention can use both solid and liquidpropellants, where the heat of combustion of liquid propellant wouldinitiate the solid propellant pellet-projectile.

The liquid propellant may be either monopropellants or bipropellants.Liquid monopropellants can be such as but not limited to nitromethane orhydrogen peroxide mixed with ethyl alcohol. In the case ofbipropellants, fuel and oxidizer are kept physically separated untilthey are injected into the combustion chamber 102. The above mentionedliquid fuel can be such as but not limited to Aniline, hydrazine hydrae,ethyl alcohol, kerosene or liquid hydrogen. Also the above mentionedliquid oxidizer can be but not limited to liquid oxygen or various formsof nitric acid.

Here the combustion of liquid propellants will generate the heatsufficient enough to trigger the initiation of solid propellant pelletprojectile.

Referring to FIG. 9B the combustion of liquid fuel in the presence ofoxidizer takes place inside the combustion chamber 102, whereby theliquid fuel arrives through liquid fuel pipeline 220 and the oxidizerarrives through oxidizer pipeline 222. The combustion of said liquidfuel produces heat that initiates the solid propellant pellet projectileexiting from the barrel 64 of gun assembly 60.

Thrust Chamber 100

Referring to FIGS. 1-6, the thrust chamber 100 generally consists of acombustion chamber and an exhaust nozzle. The thrust chamber 100 isshielded 104 on the inside with material that could withstand the heatand high pressures of combustion of propellant pellets. The abovementioned shield can be such as but not limited to ceramics or heatresisting alloys.

The shielded chamber can withstand the shocks of detonation. As shown inFIGS. 1,2,5 and 6, the thrust chamber 100 preferably consists of acombustion chamber 102 and an exhaust nozzle 106.

For the turbojet mode (FIGS. 3-4) of the invention, a turbine can bemounted on a hollow shaft in between combustion chamber 102 and exhaustnozzle 106 along the said longitudinal axis can be used. For theturbojet mode of the invention, the thrust chamber 100 can include acombustion chamber 102, turbine 130, and an exhaust nozzle 106. Thecombustion chamber 102 is generally a hollow shell of circularcross-section with one end of the said shell facing the barrel 64 of gunassembly 60 and other end generally connected to the inlet section ofexhaust nozzle 106. The combustion chamber 102 needs to be long enoughto allow complete combustion of a propellant pellet-projectile. Thecombustion chamber 102 can be shielded 104 on the inside with a materialto withstand heat and high pressures of combustion.

The turbine 130 of FIGS. 3-4 can be mounted on one end of a hollow shaft132 mounted on bearings 134. The said hollow shaft 132 can be connectedto an external gearing arrangement 136 that drives (rotates) the fanshaft 142 to power the fan 140 and a compressor 150.

The external gearing arrangement 136 delivers power from the turbine 130to the fan 140 and compressor 150. The external gearing arrangement 136can be but not limited to a speed reduction arrangement, which dependson the performance required for the aircraft.

The power from the turbine is transferred to the external gearingarrangement 136 through gear 137A coupled to the hollow shaft 132 andgear 137B respectively. From the external gearing arrangement 136 thepower is then transferred to the fan shaft 142 through gears 137C andgear 137D respectively.

The external gearing arrangement 136 is provided to clear anyobstruction to the propellant pellet projectile. Further the hollowshaft 132, on which the turbine 130 mounted; make sure any un-detonatedpropellant pellets hitting the turbine 130. The compressor 150 can beeither centrifugal or axial compressors.

Referring to FIGS. 1-6, the exhaust nozzle 106 can be of convergent,divergent, convergent-divergent, variable thrust nozzle profile or thelike.

A convergent nozzle have a decreasing cross-sectional area (FIG. 10A), adivergent have an increasing cross-sectional area (FIG. 10B) and aconvergent-divergent have a cross-sectional area that converges down tothe minimum area (throat), then diverges (FIG. 10C).

One type of variable thrust nozzle profiles have movable surfaces sothat the change in cross-sectional area can be varied, to improveefficiency. Referring to FIG. 10D the variable thrust nozzle 106 havetwo sets of moving petals (similar to petals of a flower), 107A and107B. The inside surface of 107A is in contact with the outside surfaceof 107B and by their relative movement variable thrust can be achieved.

FIG. 10A shows a convergent nozzle for use with the above embodiments.FIG. 10B shows a divergent nozzle for use wit the above embodiments.FIG. 10C shows a convergent-divergent nozzle for use with the aboveembodiments. FIG. 10D shows a moveable surfaces nozzle for use with theabove embodiments.

The selection of the above mentioned profiles generally depend on thetype of combustion in the thrust chamber that can be either detonationor deflagration and also the application for which the invention isused. Deflagration is a relatively gentle and rapid burning of fuel.Detonation is a much more powerful reaction (explosion) of the fuel andresults in such a rapid reaction that the pressure-wave created travelsat super-sonic speeds.

The cross-section of exhaust nozzle 106 can include various shapes suchas but not limited to circular, oval, square, rectangular, and the like,and combinations thereof.

Auxiliary Power System

The auxiliary power system is used for powering various systems withinthe invention. These above mentioned systems might include pelletfeeding mechanism, gun assembly, triggering system, and the variouselectrical and electronic systems.

The electric and electronic systems include control system 500. Thefunction of the said control system 500 is to control and monitor thevarious engine components such as but not limited to the triggeringmechanism, pellet feeding mechanism, control valves and gun assemblythat are present in the invention. The control system can be computers,programmable logical controllers (PLCs) or the like. For example, thecontrol system can be such as but not limited to Intel-Pentium based PCsor Motorola processor based PLCs. The control system 500 collects datafrom the various mechanisms mentioned above and act accordingly (forexample, sent signal back to mechanisms to correct their functions). Asshown in FIG. 1, the control system 500 is connected to triggeringmechanism, pellet feeding mechanism and gun assembly by cables 550. Thecables 550 can such as but not limited to control bus, optical fibers orthe like.

Referring to FIGS. 1-2, the auxiliary power system for the rocket spacemode application can preferably include piping 122 for circulatingtapped exhaust gases from the thrust chamber 100, control valves 124 forcontrolling the flow of exhaust gases through the piping 120, andoptionally small turbines 128 for powering the various systems withinthe invention.

Referring to FIGS. 3-4, the auxiliary system in the case of turbojetmode of the invention can power the fan and a compressor. The auxiliarypower can be derived from the external gearing arrangement 136 that isdriven by the turbine 130. Even though the auxiliary power system can bedesigned to use the tapped power from the propulsion system, it wouldnot limit the invention in using external power sources such asbatteries or other power systems.

FIG. 1 shows an external power system 400 that initially start up thepropulsion system (invention) by supplying power to various sub-systems(mechanisms) present in the invention. These sub-systems include pelletfeeding system 40, gun assembly 60, triggering system 80, control system500 and the like.

Housing 180

Referring to FIG. 1 for the rocket and space mode application using asolid propellant, the housing 180 can enclose the storage chamber 20,the feeding system 40, the gun assembly 60, the triggering system 80 andthe combustion chamber 102.

Referring to FIG. 2 for the rocket and space mode application using asolid and liquid propellant, the housing 180 can also enclose the liquidfuel tank 200, the oxidizer tank 202, the fuel pipelines 220, theoxidizer pipelines 222, and the pump 240 in addition to that describedfor FIG. 1.

Referring to the turbojet and ramjet applications of FIGS. 3-6, thehousing 180 covers from inlet to outlet of the respective engines.

Orientation of Components

As shown in FIGS. 1-6, the storage chamber 20 can be connected at itsoutlet 24 to the inlet 44 of the feeding channel 42 and the outlet 46 ofthe feeding channel 42 is connected to the gun assembly 60. The barrel64 of the gun assembly 60 can be positioned along a longitudinal axisX-X, preferably in the case of single-barrel gun assembly thelongitudinal axis X-X passes through the geometric center of the barrel64. The triggering system 80 can be positioned in between the gunassembly 60 and combustion chamber 102, generally surrounding the pathof the propellant pellet-projectile along the longitudinal axis X-X.

The thrust chamber 100 in the case of a rocket engine or a space vehicle(FIGS. 1-2) and a ramjet engine (FIGS. 5-6) can consist of a combustionchamber 102 and an exhaust nozzle 106, with the outlet of the combustionchamber 102 connected to the inlet section of the exhaust nozzle 106.

The thrust chamber 100 in the case of a turbojet engine (FIGS. 3-4) canconsist of a turbine 130 in between the combustion chamber 102 and theexhaust nozzle 106. The turbine 130 shown in FIGS. 3-4 can be mounted onone end of a hollow shaft 132 that has a gear connected to it. Thementioned gear drives a gearing arrangement 136 that drives the fanshaft 142 to power the fan 140 (FIGS. 3-4) and a compressor 150 as shownin FIG. 4.

The auxiliary power system in the case of a rocket engine or a spacevehicle (FIGS. 1-2) and optionally in a ramjet engine (FIGS. 5-6), cantap exhaust gases from the thrust chamber 100 through a piping 122 anduse the tapped exhaust gases to power the various systems within theinvention. The piping 122 can have control valves 124 connected to themfor regulating the flow of exhaust gases.

In the case of turbojet engine (FIGS. 3-4) the auxiliary power can bederived from the external gearing arrangement 136.

Solid and Liquid Propellants Application FIGS. 2, 4, 6

An alterative variation of the invention that uses both solid and liquidpropellants is shown in FIGS. 2, 4 and 6 of the drawings. The FIG. 2shows a rocket or space vehicle engine that uses both solid and liquidpropellants have, in addition to components mentioned for a rocketengine that uses only solid fuel (FIG. 1), a liquid fuel tank 200 and aoxidizer tank 202 can be connected to the combustion chamber 102 by fuelpipelines 220 and oxidizer pipelines 222 respectively. Both fuelpipelines 220 and oxidizer pipelines 222 can be connected to a pump 240that can be driven by the auxiliary power system. The pump 240 pumpsliquid fuel and oxidizer from their respective tanks into the combustionchamber 102. The liquid propellants mentioned above can be eithermonopropellants or bipropellants. Liquid monopropellants can be such asbut not limited to nitromethane or hydrogen peroxide mixed with ethylalcohol. In the case of bipropellants, fuel and oxidizer are keptphysically separated until they are injected into the combustion chamber102. The above mentioned liquid fuel can be such as but not limited toAniline, hydrazine hydrae, ethyl alcohol, kerosene or liquid hydrogen.Also the above mentioned liquid oxidizer can be but not limited toliquid oxygen or various forms of nitric acid. The pump 240 can be suchas but not limited centrifugal or axial pump.

FIG. 4 shows a turbojet engine that uses both solid and liquidpropellants, in addition to components mentioned for a turbojet enginethat uses only solid fuel (FIG. 3), have a liquid fuel tank 200 that isconnected to the fuel injector 204 that injects fuel into the combustionchamber 102 through fuel line 220. FIG. 6 shows a ramjet engine thatuses both solid and liquid propellants, in addition to componentsmentioned for a ramjet engine that uses only solid fuel (FIG. 5), havefuel injectors 204 and flame holders 230. The liquid fuel mentionedabove can be such as but not limited to gasoline, kerosene, diesel,alcohol, propane, butane or hydrogen. The liquid fuel is delivered intothe combustion chamber 102 in vaporized or atomized form by the liquidfuel injector 204.

Methods of Operating the Systems

A general method of operation of the invention in FIGS. 1-6 will now bedescribed. The invention uses slid propellant pellets of a selectedshape profile. The selected shape profile can be such as but not limitedto shape of a hollow bullet. Here the propellant mass is moreconcentrated at its tip (forward end) than its back. The propellantpellets that are stored in the storage chamber 20 are fed to the gunassembly 60 through the feeding channel 42 by the feeding mechanism 48.In the gun assembly 60, the ejector mechanism 62 ejects the propellantpellets through the barrel 64 at a certain velocity. The speed of thepropellant pellets can be anywhere between approximately 10 toapproximately 10000 m/s (approximately 30 to approximately 33000 fps).The requirement for a particular speed depends on the type ofpropellant, its combustion characteristics and triggering medium.

The barrel 64 gives direction to the propellant pellets ejected. Thepropellant pellet-projectiles emerging from the barrel 64 interacts withthe medium generated by the triggering system 80, causing the initiationof propellant pellets. The combustion of the propellant pellets takesplace inside the combustion chamber 102.

In the case of nuclear propellant pellet-projectiles, nuclear fissionreaction can take place inside the combustion chamber 102. The velocityand the shape profile of the propellant pellets would be such thatalmost all the combustion gases evolved would move only in the forwarddirection. Finally the hot gases expand in the nozzle 106 producingthrust for the engine. In general, the thrust produced by the inventioncan be varied by controlling the number of pellets ejected from a barrel64 in a time period and also by controlling the total number of pelletsejected at any particular instant in the case of multi-barrel gunassembly.

Generally when the time between the combustion of consecutive propellantpellets is more the system will be in pulsed mode (intermittentoperation), as the above mentioned time gap decreases the system willmove towards continuous mode (smooth operation). The time between twosuccessive propellant pellets ejected can be varied by changing the rateat which ejector mechanism 62 works. For example, the time between twosuccessive propellant pellets ejected can vary between a few nanosecondsto a few seconds. In the case of multi-barreled gun assembly 60, thetotal number of pellets ejected can be varied from all the barrelsejecting pellets at a time to each barrel ejecting in sequence.

FIG. 1 illustrates an examplary embodiment of the invention in rocketmode that uses only solid propellant pellets for propulsion. FIG. 2illustrates another examplary embodiment of the invention in rocket modethat uses solid propellant pellets as well as liquid propellants forpropulsion. In addition to the components illustrated in FIG. 1, FIG. 2contains a liquid fuel tank 200, an oxidizer tank 202, fuel pipelines220, oxidizer pipelines 222, and a pump 240. The combustion of bothsolid and liquid propellants takes place inside the combustion chamber102 and the resulting hot gases expand in the nozzle 106.

FIG. 11 shows a schematic view of a rocket/space application for usewith the embodiments of FIGS. 1-2.

FIG. 3 illustrates another examplary embodiment of the invention inturbojet mode that uses only solid propellant pellets for propulsion.The liquid fuel tank, fuel lines and fuel injector in a conventionalturbojet engine are replaced by storage chamber 20, feeding system 40,gun assembly 60 and triggering system 80 in the said mode of invention.Since the compressor in a conventional turbojet does not contribute anysignificant results in this mode of invention, it is not shown in FIG.3. The shaft 132 can be made hollow to allow any un-detonated propellantpellet projectiles to pass through. Alteratively the fan 140 can bereplaced by a propeller as in a conventional turbo-propeller engine.

FIG. 4 illustrates another examplary embodiment of the invention inturbojet mode that uses solid propellant pellets as well as liquidpropellants for propulsion. In addition to the components illustrated inFIG. 3, FIG 4 contains a liquid fuel tank 200, fuel pipeline 220, fuelinjector 204 and a compressor 150 that are present in a conventionalturbojet engine.

FIG. 12 shows a schematic view of a turbojet application for use withthe embodiments of FIGS 3-4.

FIG. 5 illustrates another exemplary embodiment of the invention inramjet mode that uses only solid propellant pellets for propulsion. Thegun assembly 60 can be preferably mounted behind the diffuser 190. Thetriggering system 80 can be preferably placed in between the taperedsections 250 to allow smooth flow of air through the engine. FIG. 6illustrates another examplary embodiment of the invention in ramjet modethat uses solid propellant pellets as well as liquid propellants forpropulsion. In addition to the components illustrated in FIG. 5, FIG. 6can contain fuel injectors 204 and flame holders 230 that are present ina conventional ramjet engine.

The air flow through the ramjet will extinguish the flame produced fromthe combustion of liquid fuel; the flame is necessary for sustainingcombustion. The flame holders 230 shied the flame from being blown outby the air flow.

The purpose of the flame holders 230 is to provide an environment wherethe fuel injected by fuel injectors 204 will burn without blowing out.Also the flame holders 230 should not obstruct the path of propellantpellet projectiles. The flame holder can be such as but not limited togutter-type or can-type. Gutter-type is just a V or U shaped piece ofmetal, alloy or ceramic material with the open side facing downwind.Can-type is usually shaped like a can made of metal, alloy or ceramicmaterial (though it may be conical, spherical or other).

Inside the gutter or can the fuel/air mixture is highly turbulent withsmall pockets of slow moving eddies. It is in these eddies that theflame is actually held without being blown out by the air flow,spreading to the rest of the fuel/air mixture.

FIG. 13 shows a schematic view of a ramjet application for use with theembodiments of FIGS. 1-2.

The invention can also be used in scramjet mode (FIG. 7) with suitablemodifications such as gun assemblies replacing some or all of thehydrogen fuel injectors and a triggering system that surrounds the pathof propellant pellets ejected from the gun assembly.

As to a further discussion of the manner of usage and operation of thepresent invention, the same should be apparent from the abovedescription. Accordingly, no further discussion relating to the mannerof usage and operation will be provided.

With respect to the above description then, it is to be realized thatthe optimum dimensional relationships for the parts of the invention, toinclude variations in size materials, shape, form, function and mannerof operation, assembly and use, are deemed readily apparent and obviousto one skilled in the art and all equivalent relationships to thoseillustrated in the drawings and described in the specification areintended to be encompassed by the present invention.

While the invention has been described, disclosed, illustrated and shownin various terms of certain embodiments or modifications which it haspresumed in practice, the scope of the invention is not intended to be,nor should it be deemed to be, limited thereby and such othermodifications or embodiments as may be suggested by the teachings hereinare particularly reserved especially as they fall within the breadth andscope of the claims here appended.

1. A propulsion system for forming propulsion from solid propellantprojectiles, comprising: a storage chamber for housing a solidpropellant pellet; a feeder for driving the pellet from the storagechamber through a feeding channel; a gun assembly connected to thefeeding channel of the feeder for ejecting the pellet as a projectile ata selected velocity through a barrel; a combustion trigger fortriggering combustion of the pellet exiting the barrel at the selectedvelocity, the triggering including a primer for generating a timeddetonation of the pellet; and a thrust generator for forming a thrustsource for a vehicle.
 2. The system of claim 1, wherein the triggerincludes: a thermal medium for initiating a thermal instability in thesolid propellant pellet.
 3. The system of claim 2, wherein the mediumfor the initiating of the thermal instability includes: a microwavegenerator.
 4. The system of claim 2, wherein the vehicle includes: anouter space vehicle for using the system.
 5. The system of claim 2,wherein the barrel includes: at least two barrels.
 6. A method ofgenerating a pressure source from combustion of a propellant, comprisingthe steps of: feeding a solid propellant pellet to a gun; ejecting thepropellant pellet from the gun through a combustion chamber at aselected velocity; triggering combustion of the ejected propellantpellet while the propellant pellet is being ejected at the selectedvelocity adjacent to the combustion chamber; and generating a pressuresource from the combustion chamber as a thrust source for a vehicle. 7.The method of claim 6, wherein the step of triggering combustionincludes the step of: initiating a thermal instability in the ejectedpropellant pellet with a thermal medium.
 8. The method of claim 7,wherein the thermal medium includes: a microwave generator.
 9. Themethod of claim 7, further comprising the step of: selecting a timedsequence for at least one of the steps of feeding, ejecting, andtriggering combustion.
 10. The method of claim 9, wherein the feeding,ejecting, triggering and generating thrust steps occurs within a singlevehicle housing.